Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
In Windows Vista and later versions of Windows, the DEVPROP_TYPE_NULL identifier represents a special base-data-type identifier that indicates that a device property exists. However, that the property has no value that is associated with the property.
Remarks
Use this base-property-type identifier with the device property functions to delete the value that is associated with a device property.
If a device property function returns this base data type, the property exists, but the property has no value that is associated with it.
The DEVPROP_TYPE_NULL identifier cannot be combined with the property-data-type modifiers DEVPROP_TYPEMOD_ARRAY or DEVPROP_TYPEMOD_LIST.
Setting a Property of this Type
To set a property whose data type is DEVPROP_TYPE_NULL, call the corresponding SetupDiSetXxx property function and set the function parameters as follows:
Set the PropertyType parameter to DEVPROP_TYPE_NULL, the PropertyBuffer parameter to NULL, and the PropertyBufferSize parameter to zero.
Set the other function input parameters as appropriate to set the property.
Retrieving a Property of this Type
A call to a SetupDiGetXxx property function that attempts to retrieve a device property that has no value will succeed and set the *PropertyType parameter to DEVPROP_TYPE_NULL.
Requirements
Header |
Devpropdef.h (include Devpropdef.h) |